A modular cell is described adapted to form a matrix of cells to support a load bearing feature such as a roadway, pavement or walkway while at the same time providing an area within the structural frame of the cell or matrix for a tree root network and/or service pipes. The cell matrix is sufficiently strong to not require filling and can instead be used as a reservoir or water collection area beneath a load bearing feature. The cell or matrix aims to accommodate the combined needs of trees, tree roots, storm water run off, roadways, pavements and walkways so that they all can co-exist in their interaction within the urban and suburban environment.
With respect to the rooting embodiment, there is a desire to introduce trees or plant matter into the landscape in order to make the urban and suburban environment more aesthetically pleasing and more conducive to good healthy living.
Nonetheless it is well recognised that plants and especially larger trees require a certain amount of space within these populated areas if they are going to develop into mature plants offering the benefits of shaded foliage, water retention, cooling, aesthetics and so forth to the surrounding area. Trees are referred to hereafter but it should be appreciated that the same analogy may be made of plants generally especially for larger plants.
For the most part, town planning has seen the planting of trees in urban and suburban areas to grow in close proximity to pavements and walkways so that the benefits of the trees can be enjoyed by those pedestrians utilising such features.
It is well recognised that for trees to successfully grow they require nutrient rich soils with the appropriate levels of moisture and sufficient drainage to allow the tree's root system to pass there through.
Alternatively, roadways, pavements, walkways and the like require a compacted and well supported soil structure to keep the positioned pavers or concrete in place thereby avoiding any structural damage to the construction and during the time of load bearing.
Hence if trees are going to be planted in urban and suburban areas around roadways, pavements and/or walkways there may be a predicament as to whether or not one needs to look after the trees and thereby provide low compact soil suitable for root growth or alternatively compact soils which provide the necessary load bearing support for the relevant roadway, pavement and/or walkway which, as noted above, would make it unconducive for the root system of the tree to develop.
More efficient water usage and storage is also a pressing issue in dry seasons or in dry climates yet water run off may often be lost through failure to capture rain and the like.
There are also increasing environmental standards requiring the capture of pollutant run off from hard surfaces.
There also needs to be sufficient area available for utilities such as piping and wiring to pass through the ground or other structures.
One solution described in PCT/AU2010/001034 is a modular cell adapted to form a structural frame of cells for supporting a load bearing feature while at the same time providing an area within the structural frame for a tree root network and/or service pipes. This design represented a major improvement on the art especially in terms of strength and load bearing capacity. One difficulty though was that the legs of this design alternated in position hence there was not a single continuous load bearing member when multiple cells were stacked vertically. A further difficulty was that the opening at the top of the modular cell was limited in size and made it difficult to ensure soil transfer through the opening and into all void spaces in the cell. In addition the walls of the cell could cause segmentation with water not flowing to all void spaces and the cell walls could also restrict access for larger service pipes to pass through the cells.
It should be appreciated that it would be useful to provide a modular cell and matrix using the cells which is able to accommodate the needs of both trees and utility lines and/or water collection and utility lines, as well as meeting the physical engineering requirements of supporting a load bearing feature, or at least to provide the public with a choice.
Further aspects and advantages of the modular cell and matrix will become apparent from the ensuing description that is given by way of example only.